Cleaning system with automatic by-pass



March l5, 1960 R. A. HETzER CLEANING SYSTEM WITH AUTOMATIC BY-PASS 3 Sheets-Sheet l Filed Aug. 3, 1956 INVENTOR. RUSSELL A. Hfrz/:R

I E A Pda,

T TORNEV March 15, 1960 R. A. HETzER 2,928,268

CLEANING SYSTEM WITH AUTOMATIC BY-PASS F/L TER INVENTOR.

RUSSEL/ A, HETZER A T TORNEV March 15, 1960 R. A. HETZER CLEANING SYSTEM WITH AUTOMATIC BY-PA/SS Filed Aug. s, 1956 WA SHER I5 Sheets-Sheet 5 a z Ts g (D 22 n3 w INVENTOA RUSSELL A. HETZER ATTORNEY p 2,928,268 y Y y y cLEANlNG sYsrnM wrrn AUroMA'nc BY-rAss Russell A. Hetzer, Fairway, Kans., assign'or to Western Laundry Machineryk Company,l a corporation of Missouri Application August 3, 1956, Serial No. 601,988

` 9 claims. (ci. ts-1s) AMy invention relates to cleaning systems, and more particularly to a cleaning system provided with an automatic by-pass for the solvent liquids used therein.

It is a purpose of my invention to provide, in Va cleaning system comprising a washer, a filter, pump and supply tank; means for preventing'air from entering-the filter and the pump that feeds the solvent liquid to the filter. My invention is applicable both to the pumping and filtering of a dry cleaning solvent soap solution or charged soap solvent and a rinsing or clear solvent. As the operation of the apparatus, wherebyair entering the filter and the pump is prevented, is the same for either the washing solution or the rinsing liquid the term solvent liquid is used in describing the solvent material that is pumped and filtered whether it be a washing solvent solution or a'rinsing solvent. In order to avoid duplication of parts in the drawings, only a single set of apparatus for preventing such entry of air into a pump and filter is illustrated,ialthough'a duplicate set of apparatus, including the by-pas'sn-nieans that'forms the subject matter of my invention; pump, filter and tank, would have to be rused in? a completetwo-bath cleaning system, with the single washer shown.`

In an apparatus of the abovereferred to character continuous. circulation of thersolvent' liquid from an ex'- tracting washer through a filter, for clarification,` fand return -to said washer is necessary, andone ofthe pure poses of my invention isv to accomplish such continuous solvent circulation, by-passing'the storage or. supply tank for such solvent liquid. Such continuous circulation of the rinsing medium is also obtained by my invention, by passing such storage or supply tank.

My invention is particularly applicable to a dry cleaning apparatus in which the supply orstorage tank, or tanks, areabove the level of the ground, which would place the same above 'the drain level of the extracting washer.` However, my 'invention is also applicable to underground storage tanks, the solvent liquid, by the application of my invention to underground storage or supply tanks, being pumped thereto instead of flowing thereto by gravity, permitting the use of smaller size piping because of the obtaining of higher drain pipeline velocity. Y J More specifically my invention comprises, in combination with a washer and a supply tank, a filter and pump'that has a discharge .connection Lleadin`g-into the filter and which has aninlet connection leading to. the' inlet of the pump `to a position in whichthe supplytank is connected with the inlet of the pump.

- Ordinarily, while the washing or rinsing operation is proceeding,unless something unforeseen occurs in the operation of the dry cleaning system, the flow from the filter to the washer and back to the pump and fromv the pumpto the filter, will be so uniform that there will be no possibility of air entering the pump or the filter. However, when the washer is being drained the flow of cleaning solvent or of rinsing solvent will be erratic, and is often reduced considerably below the capacity of the pump. When such a condition exists the valve operating means, above referred to, will respond to thscondition and adjust the valve to withdraw the liquid solvent from the storage or supply tank, thereby preventing air from entering the filter and satisfying the pump demand, so as to prevent the pump from operating in a dry condition.

' When the extraction operation of the washer is taking place thefspeed of the washer cylinder is greatly accelerated and the solvent liquid used, either vduring therinsing or-washing operation, is removed from the fabrics in the washery at an accelerated rate, causing the controlling means for the valve to move to a position such thatk the inlet of the pump is again connected with the washer instead of the storage or supply tank. As the extraction continues the flow from the washer will be reduced and the automatic valve means will again change in position to connect the inlet of the pump with the supply or storage tank.

The valve controlling means for my improved dry cleaning system is of such' a character that as soon as pump, and means for maintaining a constant flow ofV solvent liquid through the inlet connection, comprisingy valve means connected with the tank and the washer," which has one position in whichithe valve means con-VY nects the washer with the inlet connection and another position in which the valve means connects the'y tank Withzthe inlet connection, and-means-for controlling the position of the valve so that, if the flow from the washer should for any reason be diminished below that; of, the capacityof the pump, the valvelzwillgmovefromi a position in which the washer islconnected withsthe.;

- Fig 1 is adia'grammatic view, of a portion ofl a sufficient solvent liquid accumulates in the valve controlling means to properly Ysupply the pump so as to prevent air fromA entering the pump and the filter, the valve will again be adjusted' to withdraw this solvent liquid, that has come from the washer, and such back and forth adjustment of the valve means will Vtake place as-often as is necessary to withdraw all of the"v solvent liquid from the washer and yetmaintain a constant `sup ply of solvent liquid to the pump should the liow of the solvent liquid from the washer decrease below that required for supply to the pump.

The specific means for controlling the ow of solvent liquid to the pump above referred to comprises means, responsive to vthe flow of the solvent liquid from the washer toward the valve means, that determines the position of the valve, comprising a oat chamber and a float therein, that actuates controlling ymeans for the valve .to move the valve to the requiredi position. The controlling means preferably comprises means for supplying air under pressure fromfa suitablev source of supply to opposite ends of a valve operating cylinder, that has a piston therein that is connectedwith a lever for throwing the valve from one alternative position to the other. To prevent ow of solvent liquid from the `filter to the storage or supply tank during the washing or rinsingl operation a spring loaded check valve, constituting af pressure relief valve, is located between the filter "outlet and Other'objects and advantages of my' invention willappear asthe description-of the drawings proceeds. -I desire Yto have it understood, however, that I do not intend to Alimit myself to the particular details shown or described, except as defined in the claims.

In the drawings: f

, dry cleaning systemyshowing my invention applied thereto, the parts being in the position that theseV assume. when the washer is being filled with the solvent'liquid. f Y

i' Fig. 2 is a view` similar to Fig. l, showing theparts in the positionathat they,will1 assume 1 whenthe washingE or rinsing operation is being performed and the solvent liquid is being circulated in a closed circuit, including the washer, the pump and the lter, by-passing the storage or supply. tank.

Fig 3 is a similar view, showing the parts in the position that they assume when the washer is being emptied of washing or rinsing solvent and the liquid ilow from the washer is suicient to supply the pump to its full capacity. t

Fig. 4 is a diagrammatic view showing the valve controlling means in the position of the parts corresponding to that of the valve means shown in Fig. l.

Fig 5k is a similar view to Fig 4, showing the parts in the position corresponding to that of the valve means shown in Figs. 2 and 3.

Fig 6 is a vertical sectional view through one of the solenoid valves forming part of the controlling means, and

Fig. 7 is a fragmentary Vertical sectional view of the button and lint trap.

Referring in detail to the drawings, in Figs. l to 3 inclusive, is shown awasher 10, which has an inlet connection 11- and a discharge connection 12. The washer may be of any desired type that is adapted for both washing and extracting operations, which requires that the washer be provided with driving means that will rotate the washing cylinder at high speed for the extracting operation. A valve 13 is provided in the inlet connection 11, which may be manually operated, but which is ordinarily operated automatically by means of a timing device, that also controls the operations of the washer. A discharge pipe 14 from a ilter 15 is connected with the inlet connection 11, the iilter being of any well known pressure lter type. The iluid is introduced into the lter 15 through an inlet connection 16, which also comprises the outlet or discharge pipe of a pump 17, to which the inlet pipe 18 from a valve member 19 leads.

Also connected with the valve member 19 is a pipe or Y conduit '20 that extends from thel lower portion of the supply or storage tank 21, which is shown asY being above ground, and a pipe or conduit 22, which extends from a valve controlling device 23 that is interposed between the washer and the valve 19. Also, provided between the washer 10 and the valve controlling device 23, is a lint and button trap 24, which is provided with a weir 25, over which the uid medium passes when the washer is filled to the normal washing or rinsing level thereof, as shown in Fig. 2 of the drawings.

A conduit or pipe 26 extends from the lint trap 24 to thevalve controlling device 23. The pipe or conduit 26 extends from the opposite side of the Weir 25 from that to which the pipe or conduit 12 leads from the washer 10. The trap 2,4 has an outlet connection 27, to which the pipe 26 is connected, andV has a bottom opening 28 adapted to be closed by the valve 29 leading to the passage 30 in the false bottom 31 leading to the outlet connection 27 under the Weir 25, which preferably has a xed lower portion 32 and an adjustable upper portion 33. The position of the valve 29 may be determined by a suitable timing device, but is shown as being controlled by means of a lever 34 and valve operating rod 35 in the drawings. j

The valve operating member 23 is provided-with a float chamber in which the float 36 is located. It will be noted that the conduit or pipe 26 enters the upper portion of the float chamber of the controlling member 23 and that the pipe or conduit 22 extends from lthe lower portion thereof. As long as the flow of solvent liquid such as the washing solvent solution or the rinsing solution is entering through the pipe or conduit 26 `at the same or a greater rate than that at which it is being withdrawn therefrom by the pump through the pipe or conduit 22, the oat 36 will be in the raised position shown in Figs. 2 and 3. If the rate of withdrawal through the pipe 22 by the pump 17 is greater than that at which the solvent is being supplied through the pipe or conduit Y 26 the float will drop to the position shown therefor in The oatroperated controlling device is indicated generally by the numeral 37 in Figs. 1, 2 and 3. It is shown diagrammatically in Figs. 4 and 5. The oat is provided with a suitable stem 38 that has a pair of collars 39 and 40 provided thereon, that control the position of the switches 41 and 42,'respectively. When the float 36 is in the down position shown in Fig. l the collar 39 engages the operating member of the switch 41 to move the same to circuit closing position. When the oat 36 is in raised position, as shown in Figs. 2 and 3, then the collar 40 engages the operating member of the switch 42 to move the same, to circuit closing position. Y Y

Referring now to Figs. 4.and 5, the operating circuit for the controlling device is shown as comprising a pair of conductors 43 and 44 extending from the linewires 4S and 46. The conductor 44 is provided with a branch 47 extending to one terminal of the solenoid valve 48, the other terminal of said valve 48 having a conductor 49 extending therefrom to the switch 41, whichis adapted to engage a stationary contact that is connected 4with the conductor 43 through a conductor 50. A branch fconductor 5,1 also extends from the conductor 44 to' one termina-l Vof a solenoid valve 52, the other terminal of which is connected by means of a conductor S3 with the switch 42, which is adapted to engage a stationary contact from which a conductor 54 extends to the conductor 43.

The conduit 55 extends from a source of air under pressure and is provided with branches 56 and 57 leading to the solenoid valves 48 and 52, respectively. Each of said solenoid valves also has a vent pipe extending therefrom to the atmosphere, the vent Vfor the valve 48 being indicated bythe numeral 58 and the vent pipe for the valve 52 being indicated by the numeral 59. A conduit 60 extends from the-solenoid valve 48 to one end of a cylinder 61 and a conduit 62 extends from the solenoid valve52 to the other end of the cylinder 61. Said cylinder is provided with a piston 63 therein, which is connected through a rod 64 with a lever 65 that controls the position of the valve 19. l

In Fig. 6 is shown a solenoid valveof the general character of the valves 48 and 52, which are alike in construction. Said valve has a body portion 66 which has an inlet connection 67, which is connected with either the pipe 56 or the pipe 57,` leading to the source of air under pressure and a threaded opening 68, with which the pipe 60 or 62, as the case may be, leading to the cylinder 61, is connected. Said valve is provided with a screw-threaded opening 69 leading to an air vent pipe, such` as the air vent pipes 58 and 59. A passage 70 leads to thev air vent connection 69 from a valve seat 71 and a movable valve member 72 is provided, which has a suitable sealing member 73 provided thereon for A engagement with the Vvalve seat 71. Said movable valve member also has sealing means 74 provided thereon for engagement with a valve seat 75, to which a passage 76 extends, which leads from the inlet connection 67. The spring 77 holds the movable valve member 72 normally Vin engagement with the valve` seat 75 so as to close the passage 76. A rsolenoid winding 78 is'provided in the valve, which, when energized, moves the movable valve member 72, which serves as a movable core' in the solenoid, toward Ythe seat 71 and away from the seat 75. There are airpassages 79 provided around the movable valve member`72 for ow of air to the Vent pipe connection 69. Y

It.will betobvious that when the solenoid winding 78 is energized in the solenoid valve 48 thel pipe 56 supplying air under pressure will be connectedrwith the pipe 60 and, similarly, when the solenoid winding 78 of the solenoid Y valve 52 is energized the pipe 57 will be connected with the pipe 62 to supply air under pressure vto, the cylinder ,61. Qn the other hand, when `the solenoids of the valves 48 and 52 arede-energizedthen theV pipes 60 and 62, respectively, will be connected through said valves 48, and 52 with the air ventzpipes I 58A and 59.

, When the iloat is in the raised position shown in Figs. 2 and 3 the rod 38 will be in a raised position and the switch 42 will be closed, energizing the solenoid in the valve 52 and supplying air under pressure to the left hand end of the cylinder 61. At this time the switch ,41`is in open position and the right hand end of the cylinder 61, as viewed in Figs. 4 and 5, will be vented to the atmosphere. With the lioat in such raised position the connection from the air pressure supply pipe 57 tothe cylinder 61 is through the passage 76 of the valve 52 to the pipe 62, and the connection to the air vent 58 is throughr the pipe 60 through the passages. 79 and 70 of the valve 48 to the air vent 58. When the float 36 is in the down position, as shown in Fig; l, the switch 42 will be open and the switch 41 will be closed, because the rod 38 is in a lowered position, and the air pressure supply pipe 56 will be connected in a similar manner to that explained abovethrough the solenoid valve 48, which will have its solenoid'winding energized, with the vpipe'60 leading to the right hand end of the cylinder 61, while the vent 59 will be connected iny a vsimilar manner tothat explained above with the pipe 62 leading from the left hand end of thel cylinder 61"throughthe solenoid valve 52. l

-The valve 19 has a rotatable valve member 80 therein, which has the aligned passages 81 and 82 and a passage 83 extending perpendcularly to Vthevpassages 81 in order for the solvent liquid to vreach the'oonduit 26 l ithasto flow; over the Weir 25. `As soon. as sufficient solventliquid has entered the float chamber of Atheconltrolling device 23 to raise the loat 36, the rotatable valve member 80 in the valve 19 will be turned to the position shown in Fig. 2. In that position of the valve the pipe or conduit 22 is'connected with the pipe or conduit 18 through the-passagesL'SZand 81 of the rotatable valve member 80, `the movement of the valve having taken place due to the piston 63 having been moved from the position shown in Fig. 4 to that shown in Fig. 5 due to the closing of the switch 42 and1opening of the switch 41. Circulation of the washing solvent solution or the rinsing solvent will continue for the desired length of time, by-passing the tank 21,the ow being from the washer .through the lint and button trap 24, the valve controlling device 23, the .pump 17, the lter 15 and back to the washer.

' f The next operation'consists of draining the washer of and 82, all said passages being connected together. I-t

will be noted that when the oat 36 is in raised position the valve 19 will be in the position shown in Figs. 2 and-3 due tothe fact 'that the piston 63 will have been noved to the position shown in Fig. 5, as, 'in thisy position of the oat the switch 42 is closed and air under pressure is supplied to the left hand side of the cylinder 61, while the right hand side thereof is vented to the air. When thefloat 36 has dropped to the position shown in FigT 1 the piston 63 will be moved to the left due to the Afact that the switch 42 will be opened and the switch 41 closed'because of downward movement of the rodlike member 38, and air under pressure Will be supplied to the right hand end [of the cylinder 61 through the pipe 60'and the left hand side of the cylinder 61 will be vented through the pipe 62, the valve 19 thenbeing moved to the position shown in Fig.1 due to the swinging of the lever from the position shown in Fig. S to that shown inr Fig. 4. The tank 21 is connected with vthe outlet or discharge pipe 14 of the filter and the.

inlet pipe orconduit 11 Yof the washer through a pipe 84 leading into the top of the tank, which pipe is pro'- vided with a spring loaded check valve 85 opening toward the tank 21 when the valve 13 is closed, said valve 85 thus serving as, a pressure relief valve.

In the operation of my improved drycleaning apparatus A the washer 10 is filled with liquid washing solvent solution orf clear solvent fort rinsing by opening of the valvel 13.' At the time that this operation is started the: washer 10 is empty of solvent liquid and the float chamberof thev controlling device 23 is also empty, the float 436 then being in the down position shown in Fig. 1. Thevalve 19-will` then Vconnect the pipe or conduit 20 leading from the'tank 21 -with the pipe or conduit 18 leading to the pump 17 lthrough the passages 81 and 83 in sai dy valve member, and the solvent liquid will, be pumped from-the tank'21 throughthe conduit 16, filter 15, conduit l4and7condu'it 11 to the wa'sher.

' This will continue until the washeris filled to the desired level, which is determined bythe position of the top of-the adjustable top member 33 of theweir 25. The -yalve willbe in the position shown in Fig. l so `that the solvent,liquidywhether it be a washing solvent soap solutionor a clear rinsing solvent. When this operation commences the valve 13 is closed and thevalve 29 is moved to` the position shown in Fig. 3 by a suitable timing means, or manually, if no timing means is provided therefor. Upon closing the valve k13 the valve 85 will open due to the increase in pressure in the pipes or conduits 14, 11, and the portion of the conduit 84 on the right hand side of the valve 85, and the flow of the solvent ,liquidgwill bey from the washer 10 through the conduit 12, passage 30 and through the conduit 26 to the valve controlling device 23 and from that through the pump 17 and filter 15, conduits 14 and 84 to the storage or supply tank 21, the valve 19 having its rotatable valve member retained Yin the position shown in Figs. 3 vand 4 as long as the Viiow of solvent liquidvfrom thewasher 10 is sufficient to supply the pump 17.Y However, if the flow decreases through the conduit 26 so that it is less than that which the pump 17 tends towithdraw through lthe conduit22, the oat36 will droprto the Position shown in Fig.l 1, the switch 41 will be closed andthe switch 42 opened and the piston 63 will move to the posi- -tion shown in Fig.'4 and the valve member 19 will move `to thel position shown in Fig. 1, whereupon the pump 17 will circulate the solvent liquid through the filter 15 and tank 21so that the pump 17 will always be supplied with sufficient liquid to keep air from being drawn into the same and the filter `1-5 will always be kept filled with lthe solvent liquid, which will keep the filter operating at full efiiciency.'

The next ioperation, whether the solvent liquid withdrawn from the washer was a solvent soap solution or a clear rinsing solvent, is the extracting operation. When the extracting operation starts the ilow of solvent liquid from the washer increases, and this will cause the iioat chamber to fill so that the float 36 will again rise and the valve .member 19 will again move to the position shown in Figs. Zand 3 and this position will be maintained for the valve as long as a regular flow of solvent liquid into the controlling member 23 suicient to supply the pump 17 is occurring. The solvent liquid will, in this position of the valve, be pumped from the washer through the various apparatus shown in the drawings to the filter and described. The arrows on Figs. 1 to 5 of the drawings v.

indicate the direction'of flow of the solvent liquid under various -conditions between the various apparatusyand through certain of said apparatus including the Vsolenoid valves shown in Figs. 4 and v5.`v

What I claim is:

1. The combination with a washer and a solvent liquid supply tank, of a filter, conduit means extending from theV outlet of said filter to the inlet of said washer, a branch conduit extending from said conduit means to said supply tank, a normally closed check valve in said branch conduit responsiveto pressure in said conduit means to connect the outlet of said filter with said tank, a. pump having a discharge connection leading into said filter, an inlet connection leading to said pump and means for maintaining a constant iiow of said solvent liquid through said pump inlet connection comprising valve means, conduit means connecting said valve means with said pump inlet connection, said tank and the washer outlet, said last mentioned valve means having a position connecting said washer outlet with said pump inlet connection and a position connecting said tank with said pump inlet connection, a solvent liquid accumulating -chamber interposed between said washer outlet and said last mentioned valve means, and means responsive to the level of said solvent liquid incsaid chamber controlling the position of said last mentioned valve means.

2. The combination with a washer and a solvent liquid supply tank, of a filter, conduit means extending from the outlet of said lter to the inlet of said washer, a branch conduit extending ffrom said conduit means to said supplytank, a normally closed checkvvalve in said branch conduit responsive to pressure in said conduit means to connect the outlet of said filter with said tank, a pump having a discharge connection Vleading into said filter, an inlet connection leading to said pump and means for maintaining a constant iiow of said solvent liquid through said pump inlet connection comprising valve means, conduit means connecting said valve means with said pump inlet connection, said tank and the washer outlet, saidlast mentioned valve means having a position connecting said washer outlet with said pump inletV connection anda position connecting said tank with said pump inlet connection, and float actuated means interposed in the conduit means connecting said washer toutlet with said last mentioned valve means between said washer outlet and said last mentioned valve means controlling the position ofisaid last mentioned valve means.

3. The combination with a washer and a solventiiquid Supply tank, of a filter, conduit means extending fnom the outlet of said filter to the inlet of said washer, a branch conduit extending from said conduit means to said supply tank, a normally closedcheck valve insaid branch co-nduit responsive to pressure insaid conduit means to connect the outlet of said filter with said tank, a pump having a discharge connection leading into said filter, an inlet connection leading to said pump and means for maintaining a constant iiow of said solvent liquid through said pump inlet connection comprising valve means, conduit means connecting said valve means with said pump inlet connection, said tank and the washer outlet, said last mentioned valve means havinga position connecting said washer outlet with said pump inlet connection and a position connecting said tank with said pump inlet connection, means for moving said last mentioned valve means from either of said positions to the other thereof, a solvent liquid accumulating chamber interposed between said washer outlet and said lastmentioned valve means, and means responsive to theY level of said solvent liquid in said chamber controlling the operation of said means for moving said valve means.

4. The combination with a washer and a solvent liquid supply tank, of a filter, conduit means extending from the outlet of said filter to the inlet of said washer, a branch conduit extending from said conduit means to said supply tank, a normally closed check valve in said branch conduit responsive to pressure in said conduit means to connect the outlet of said filterY with said tank, a pump having a discharge connection leading into said filter, an inlet connection leading to said pump and means for maintaining a constant flow of said solvent liquid through said pump inlet connection comprising valve means, conduit means connecting said valve means with said pump inlet connection, said tank and the washer outlet, said last mentioned valve means having a position connecting said washer outlet with said inlet connection and a position connectingsaid tank with said v inlet connection, means for moving said last mentioned valve means from either of said positions to the other thereof, and lioat actuated means interposed in the conduit means connecting said washer outlet with said last mentioned valve means between said washer outlet and said last mentioned valve means controlling the operation of said valve moving means.

5. The combination with a washer and a solvent liquid supply tank, of a filter, conduit means extending from the outlet of said filter to the inlet of said washer, aA branch conduit extending from said conduit means to said supply tank, a normally closed check valve in said branch conduit responsive to pressure in said conduit means to connect the outlet of said filter with said tank, a pump connected to said filter to discharge said solvent liquid into the same, valve means having a tank connection, a washer outlet connection and a pump connection and having a valve member having a position connecting said pump connection with said washer outlet connection'and a position connecting said pump connection with said tank connection, a solvent liquid accumulating chamber in said washer outlet connection between the outlet of said washer and said last mentioned valve member, and means controlling the position of said last mentioned valve member comprising a iioat in said chamber having a position responsive to the level of said solvent liquid therein and valve actuating means responsive to the position of said oat.

6. The combination with a washer and a solvent liquid supply tank, of a filter, conduit means extending fromthe ,outlet of said filter to the inlet of said washer, a branch conduit extending from said conduit means to said supply tank, va normally closed check valve in said branch conduit responsive to pressure in said conduit means to connect the outlet of said filter with said tank, a pump connected to said filter to discharge said solvent liquid into the same, valve means having a tank connection, al washer outlet connection and a pump connection and having a valve member having a position connecting said pump connection with said Washer outlet connection and a position connecting said pump connection with said tank connection, and means controlling the position lof said last mentioned valve member interposedbetween said washer and valve, said controlling means having a oat chamber in said washer outlet connection receiving tiuid medium discharged from said washer, a iioat in said chamber, a valve member operating lever, a cylinder,

a piston in said cylinder and connected with said lever, and means for moving said piston comprising iioat controlled valve means for supplying tiuid under pressure to said cylinder on one side of said piston in raised position of said iioat and on the other side of said piston in lowered position of said float.

, 7. The combination with a washer` and a solvent liquid supply tank, of a filter, conduit means extending `from the outlet of saidiilter to the inlet of said washer, a branch conduit extending from said conduit means to said supply tank, a normally closed check valve'in said branch conduit responsive to pressure in said conduit means to connect the outlet of said filter with said tank, a pump connected to said filter to discharge said solvent liquid into the same, valve means having a tank connection, a washer outlet connection and a pump connection and having a valve member having-a position connecting said pump connection with said washer outlet connection and a position connecting said pump connection with said tank connection, and means controlling the position of said'last mentioned valve member interposed between saidr washer and valve, said controlling meansl having a float chamber in said washer outlet connection receiving solvent liquid discharged from said washer, a float in said chamber, a valve operating lever, a cylinder, a piston in said cylinder and connected with said lever, and oat contnolled valve means for supplying iiuid under pressure to said cylinder on one side of said piston in raised position of said `iioat and on the other side of said piston in lowered position of said float.

8. The combination with a washer and a solvent liquid supply tank, of a lter, conduit means vextending from the outle-t of said filter to the inlet of said washer, a branch conduit extending from said conduit means to said supply tank, a normally closed check valve in said branch conduit responsive Yto pressure in said conduit means n to connect the outlet of said iilter 'with said tank,

a pump connected to said filter to discharge said solvent liquid into the same, valve means having a tank connection, a washer outlet connection and a pump connection and having a valve member having a position connecting said pump connection with said washer outlet connection and a position connecting said pump connection with said tank connection, air pressure actuated means controlling the position of said last mentioned valve member and controlling means or said air pressure actuated means comprising a solvent liquid accumulating chamber in said Washer outlet connection between said Washer outlet and said last mentioned valve member, a iloat in said chamber having a position responsive to the ievel of said solvent liquid in said chamber and float oontrolled means controlling the supply of air under pressure to said air pressure actuated means.

9. In a dry cleaning system, a washer, a liquid supply tank, a filter, a pump discharging into said iilter, a discharge connection from said ilter having branches extending to said Washer inlet and tank, conduit means ex- Vso tending from said washer outlet and from said tank and v conduit means leading to said pump, means for establishing a closedcircuit for circulation of said liquid including said filter, pump and washer and by-passing said tank,

comprising a valve in one of said branches controlling References Cited in the iile of this patent UNITED STATES PATENTS 2,085,820 Mills et al.,V Iuly`6, 1937 2,087,775 Matthews July 20, 1937 2,359,138 Martin Sept. 26, 1944 2,729,961 Shields Jan. 10, 1956 Creswick Oct. 30, 1956 

